Bottle cap



March 1956 R. G. MATTOX 2,738,091

BOTTLE CAP Filed Jan. 11, 1954 F1 EL;

FIBE- INVENTOR. v 08587 GMA 770A ATTORMEV:

United States Patent The self-venting bottle cap comprising the presentinvention is primarily adapted for use in connection with bottles orjugs having reduced threaded neck portions providing relatively narrowmouth openings, although the principles of the invention are applicablefor use in con-' nection with jars or other receptacles having widermouth openings.

A bottle cap such as. described herein is particularly useful in sealingbottles containing fluids which would become contaminated upon contactwith air, since the bottle can be filled directly to the top and the airtrapped by the cap is vented during the screwing-on operation. Once thebottle cap is in place air cannot re-enter the bottle.

A bottle cap such as disclosed herein is also particularly useful in thestoring of certain chemicals which could generate high gas pressureswithin the container and blow ofi the cap or explode the container.

The principal object of the invention is to provide a cap for a bottleor the like, wherein said cap contains a seal which automaticallyoperates to relieve excessive pressures developed or generated withinthe bottle, but will not permit gas or liquid from outside the bottle topenetrate therewithin.

Other objects of the present invention will be apparent from thefollowing description taken in connection with the accompanyingdrawings, wherein:

Fig. l is a perspective view of a bottle cap embodying the principles ofmy invention, the sealing member being removed and certain parts beingbroken away to reveal the details of other parts.

Fig. 2 is a bottom view of the bottle cap shown in Fig. 1. V

Fig. 3 is a sectional view of the bottle cap shown in Fig. 1 in place ona bottle, the section being taken along line 3-3 of Fig. 2.

Fig. 4 is a plan view of the sealing member.

Fig. 5 is a sectional view taken on line 55 of Fig. 4.

The reduced neck portion of the bottle is designated at and is providedwith inner and outer surfaces that are substantially cylindrical. Theusual threads 11 are formed on the neck to accommodate a bottle cap 12having a depending skirt portion 13 with internal threads 16 formedthereon. The upper rim 14 of the bottle opening provides a flat sealingsurfacedesigned for coextensive sealing engagement with a resilientdisc-shaped liner 15 mounted within the cap 12.

The inner surface of the cap 12 has a depending cylindrical centerportion 17 of slightly smaller diameter than the bottle opening, and aplurality of relatively narrow webs 18 extending radially from saiddepending center portion to the skirt 13. The height of the centerportion 17 and the webs 18 is approximately one-half the thickness ofthe liner 15.

Under normal conditions of pressure within the bottle, the resilientliner 15 is compressed between the rim 14 and the webs 18, and theportion of the liner adjacent the area between the webs 18 remains insealing contact with rim 14 by virtue of the inherent resiliency andstiffness of the liner. Under conditions of excessive pressure withinthe bottle, the liner becomes flexed in the area between the webs 18,and the excess pressure bleeds ott'to the atmosphere through thetortuous path provided by the threads 11.

It is obvious that by varying the resilience (and can sequently thestiflfness) of the liner 15, or the circumferential length between thewebs 18, the bottle may automatically be caused to become vented to theatmosphere within reasonably definite ranges of internal pressure.

From the foregoing description it may be seen that the present inventionprovides a novel form of cap for a container which will permit completefilling of the container since any air trapped in the container will bevented by the cap as it is screwed onto the container.

It is further evident that by employing a novel cap such as disclosedherein any high gas pressure which may be generated within the bottlewill be vented to the atmosphere in order to prevent the cap from beingblown off or the container from exploding.

While I have shown and described the preferred form of my invention, itis to be understood that various changes may be made in its constructionby those skilled in the art Without departing from the spirit of theinvention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A cap for use on a container having a mouth defined by a topcircumferential lip comprising means for interengaging said cap andcontainer for holding said cap to said container, a disc-shapedresilient liner in said cap adapted to sealingly engage saidcircumferential lip, a depending cylindrical portion in said cap ofsmaller diameter than the opening in said container, a plurality of websextending radially from said depending center portion to the skirtportion of said cap for pressing said liner against said hp at apredetermined number of points around said lip.

2. A cap for use on a container having a mouth defined by a topcircumferential lip comprising means for interengaging said cap andcontainer for holding said cap to said container, a disc-shapedresilient liner in said cap adapted to sealingly engage saidcircumferential lip, 8 depending cylindrical portion in said cap ofslightly smaller diameter than the opening in said container, aplurality of webs extending radially from said depending center portionto the skirt portion of said cap for pressing said liner against saidlip at a predetermined number of points around said lip, the height ofsaid depending center portion and of said webs being approximatelyone-half the thickness of said resilient liner.

3. A cap for use on a container having a mouth defined by a topcircumferential lip comprising means for interengaging on said cap andcontainer for holding said cap to said container, 2. disc-shapedresilent liner in said cap adapted to sealingly engage saidcircumferential lip, a depending cylindrical portion in said cap ofslightly smaller diameter than the opening in said container, aplurality of webs extending radially from said depending center portionto the skirt portion of said cap for pressing said liner against saidlip at a predetermined number of points around said lip, the height ofsaid depending center portion and of said webs being approximatelyone-half the thickness of said resilient liner, and adhesive meansfastening said liner to said depending center portion.

References Cited in the file of this patent UNITED STATES PATENTS1,648,793 Weber Nov. 8, 1927 2,032,931 Gibbs Mar. 3, 1936 2,138,376Griswold Nov. 29, 1938 2,514,124 Eisen July 4, 1950 2,576,917 BennerDec. 4, 1951 FOREIGN PATENTS 448.154 Great Britain June 3, 1936

